#include<iostream>
#include<vector>
#include<string>
#include<pthread.h>
#include <semaphore.h>
template<typename T>
class RingQueue
{
    private:
    void P(sem_t &s)
    {
        sem_wait(&s);
    }
    void V(sem_t &s)
    {
        sem_post(&s);
    }
    public:
    RingQueue(int max_cap):_ringqueue(max_cap),_max_cap(max_cap),_c_step(0),_p_step(0)
    {
        sem_init(&_data_sem,0,0);
        sem_init(&_space_sem,0,_max_cap);
        pthread_mutex_init(&_c_mutex,nullptr);
        pthread_mutex_init(&_p_mutex,nullptr);



    }
    void Push(const T&in)
    {
        P(_space_sem);
        pthread_mutex_lock(&_p_mutex);//这里的信号量要在所之前信号量是预定票，而锁则是安检
        _ringqueue[_p_step]=in;
        _p_step++;
        _p_step%=_max_cap;
        pthread_mutex_unlock(&_p_mutex);
        V(_data_sem);
    }
    void Pop(T *out)
    {
        P(_data_sem);
        pthread_mutex_lock(&_c_mutex);
        *out=_ringqueue[_c_step];
        _c_step++;
        _c_step%=_max_cap;
        pthread_mutex_unlock(&_c_mutex);
        V(_space_sem);
    }
    ~RingQueue()
    {
        sem_destroy(&_data_sem);
        sem_destroy(&_space_sem);
        pthread_mutex_destroy(&_c_mutex);
        pthread_mutex_destroy(&_p_mutex);
    }

    private:
    std::vector<T>_ringqueue;
    int _max_cap;
    int _c_step;
    int _p_step;
    sem_t _data_sem;
    sem_t _space_sem;
    pthread_mutex_t _c_mutex;//这里多对多时同类的也是竞争者所以需要两把锁
    pthread_mutex_t _p_mutex;



};